I think the new immersive Windows Mixed Reality headsets are great. On the other hand, for me UWP is just annoying.
For example I want to develop applications that can freely access files without sandboxing.
As far as I understand, currently Unity requires to build for UWP if you want to use the immersive headsets.
Is there perhaps a work around to use the headsets without building for UWP?
Thanks a lot!
Not currently. UWP is not all that bad, sandboxing is a common practise on consoles and mobile so getting used to it for pc will make any possible porting easier.
If this is an option for you, you can already use Windows MR headset on OpenVR sdk through ‘Windows Mixed Reality Steam VR preview’.
I was looking into that but as far as I understood it is still a closed preview, or?
I guess I will then just have to wait until it goes public.
I think this is ok when you develop a game but Unity is meanwhile also used for other applications and then UWP is not always an option.
Given that the Unity Editor (not a UWP app) works directly with the Mixed Reality headsets, it’s certainly possible to write an app that uses the headsets without UWP. Microsoft wants everyone to move to UWP though, and Unity appears to be supporting that by making UWP builds the only option.
Add me to the list of people who would like to have the Unity Editor WMR support in the basic standalone windows Unity Player. 
If it’s not already done, you’ll have to fill out the form here https://aka.ms/iwantmr? . If you are already into the program then try to ask Microsoft MR team directly.
Did anything change since this was discussed? SteamVR is not viable for business use, but the still immature UWP and Visual Studio workflow are incompatible with very functional Unity’s plugins like Bolt or even Playmaker. With long build times and little data online other than Microsoft’s scrambled documentation I need a way out, I can’t add months to this project.
I’ve been watching this discussion and waiting for a reply to the previously asked question. Has anything changed with regards to this topic? I need my project to be compatible with both WMR and Oculus, but my project acts strangely when using a UWD build, so I’d rather use universal. The only issue in universal mode is my WMR headset doesn’t change the camera’s position (only orientation), whereas my Rift S does, so I’m only getting 3dof with WMR.
There is currently one option to use WMR headsets without UWP. Download Unity version 2019.3xx or above, try new XR input manager, choose Mixed Reality and you are good to go. The only problem is that you need to use legacy input and write interactions from scratch. Or maybe not, didn’t test it with XR interaction toolkit or something similar, so let me know if someone does 